Mixed ligand complexes of AEE hexafluoroacetylacetonates with diglyme: Synthesis, crystal structure and thermal behavior

摘要

The novel mixed ligand complexes [Ca(hfa)(2)(diglyme)(H2O)] (I), [Sr(hfa)(2)(diglyme)(H2O)1 (II) and [Ba(hfa)(2)(diglyme)(2)] (III) (Hhfa = 1,1,1,5,5,5-hexafluoropentane-2,4-dione, diglyme = 2,5,8-trioxanonane) were synthesized by the reactions of the alkaline earth element (AEE) carbonates in n-hexane with a mixture of Hhfa and diglyme, and they were characterized by elemental analysis, H-1 and C-13 NMR, and FTIR spectroscopy. The crystal structures of I-III, consisting of mononuclear isolated molecules, have been determined. The thermal behavior and composition of the vapor phase have been studied for I-III by thermal analysis at low pressure and mass spectrometry using a Knudsen cell. The stability of the mixed ligand complexes [M(hfa)(2)(diglyme)(n)] to the removal of diglyme molecules under heating decreases in the row I > II approximate to III, and only I evaporates as the mixed ligand complex after water removal. (C) 2008 Elsevier Ltd. All rights reserved.